.parent {
  display: flex;
  flex-wrap: nowrap;
  width: 400px;
  height: 400px;
  background-color: yellow;
  align-content: space-between;
}

.parnet .child {
  width: 30px;
  height: 30px;
  background-color: red;
}

.parent .child:nth-child(1) {
  align-self: center;
  width: 30px;
  height: 30px;
}

.parent .child:nth-child(2) {
  align-self: center;
  width: 30px;
  height: 30px;
}

.parent .child:nth-child(3) {
  align-self: center;
  width: 30px;
  height: 30px;
}